Control system



April 14, 1942. w. v. HOBBS CONTROL SYSTEM Filed May 31, 1940 2 Sheets-Sheet l W H'c v \fffi BY QQM ZZW;

ATTORNEY April 14, 1942. w. v. HOBBS- 2,279,338

CONTROL SYSTEM Filed May 3-1, 1940 2 Sheets-Sheet 2 lNV NTOR Her H bbs \SQ HRF M. ATTORNEY 5 Patented Apr. 14, 1942 Walter v. Hobbs, Columbus; out, asaignor to Dance incorporated, Columbus, Ohio, acorporation of Ohio Application May 31, 1940, Serial No. 338,002

23 Claims.

The present invention relates to refrigerating apparatusand particularly to the control of the apparatus from a plurality of different refrigerated zones.

One of the objects of the present invention is to provide a refrigerating apparatus in which the running phase and the inactive phase of the cycle of the refrigerant circulating mechanism is controlled by a system containing a volatile liquid and in which the change in temperature or pressure in the system is utilized for changing from one phase of the cycle of the circulating mechanism to the other when gas of the liquid recondenses in a portion of the system which is always subjected to the temperature of the heat absorber and from which it overflowed during the said one phase of the cycle.

Another object of the present invention is to provide a refrigerating apparatus in which the phases of operation thereof are controlled by a system containing a volatile liquid and in which changes in temperature are utilized to vary the capacity of a portion of the system so that at times, the capacity thereof is insufficient to hold all of the liquid whereby the liquid flows to another portion of the system which is subjected to a diflerent refrigerating temperature and in which the change in temperature or pressure in said other portion of the system, when gas oi the liquid recondenses in the first mentioned portion, 1

is utilized for changing from one phase of operation of the system to the other.

Other and further objects and advantages will be apparent from the following description, reference being had to the accompanying drawings wherein preferred forms of embodiments of the present invention are clearly shown.

In the drawings: Y

Fig.1 is a diagrammatic view showing one form of the invention;

Fig. 2 is a diagrammatic view of the fluid system of the control showing liquid in a plurality of remote portions of the system;

Fig. 3 is a view similar to that shown in Fig. 2,

p but showing all of the liquid in one portion of the system;

Figs. 4, 5 and 6 are diagrammatic views of control systems, each showing a different embodiment of the invention;

Fig. 7 is a diagrammatic view of a refrigerating apparatus and also a diagrammatic view of a control system, which control system shows another embodiment of the invention;

Fig. 8 is a diagrammatic view of a portion of the control system shown in Fig. 7, and showing all of the volatile liquid in one portion of the control system, and a Fig. 9 is a view similar .to Fig. 8 but showin part of the liquid in two portions of the control system.

Referring to. the drawings and particularly Figs. 1, 2 and 3, there is shown, for the purpose 'of illustrating one form of the invention, a refrigerating system of the compressor-condenserexpander type wherein the heat absorber is illustrated as the evaporator 20, and the means for circulating refrigerant through the evaporator as a compressor 2|. The evaporator includes a header 23 from which depends tubular'walls 24. The header may contain a float valve (not shown) for controlling the flow of refrigerant from the condenser 25 to the evaporator 20. Gaseous ref rigerant is withdrawn from the header 23 by the compressor 2i through the pipe TI. The refrigerant is compressed by the compressor 2| and forced into the condenser 25, whence the liquid refrigerant flows to the header by pipe 28.

The circuit for the compressor 2| includes a wire and wire 3|, stationary contact 32, movable contact 33, stationary contact 34 and wire 35. The contact 33 is actuated by a suitable snap acting mechanism 31 which is diagrammatically shown as including two levers 38 and 39 plvotally supported at 40 and interconnected by a spring 4|. Operating movement is imparted to the lever 39 by abellows 43 and this operating movement is translated into snap acting movement of the lever 38 by moving the spring 4| oneither side of its dead center position with respect to the pivot 40.

The control system, generally indicated by 45 includes the bellows 43, a bulb 46 and a bulb 41. Bellows 43 is connected to bulb 46 by a tube 49 and the bulb 46 is connected to the bulb 41 by a tube 50. Preferably the tubes 49 and 50 are of very small diameter and are generally referred to by the trade as capillary tubes.

The evaporator 20' and the bulbs 46 and 41 are contained within an insulated compartment 52.

. The bellows 43 and the switch mechanism may be disposed outside of the compartment 52, provided the outside temperature is always above the temperature in the compartment, but in the present embodiment they are also inclosed.

In the present embodiment the bulb 41 is in intimate thermal contact with the evaporator 20 and therefore assumes -or closely follows the temperature of the evaporator while the bulb 45 is disposed remotely from the evaporator and consequently is subjected to the medium, in this .perature, the pressure within particular example air, cooled by the evaporator. The system 45 contains a limited quantity of volatile liquid which liquid. as a liquid, expands and contracts when subjected to increased and decreased temperatures. The capacity of the bulb 41 and the quantity oiliquid contained in the system is so computed that all of the liquid of the system is contained in the bulb 41 when the evaporator is at the desired minimum temperature. When the temperature or the evaporator and likewise the liquid within bulb increases, the liquid expands and flows into the bulb 46 through the tube 50. The liquid in the bulb 48 will then be responsive to the temperature or the air in the compartment 52 remote from the evaporator 20. When the pressure within the system attains a predetermined high value, computed with the desired maximum temperature of the air at the position of the bulb 46, the bellows will have expanded suillciently to move the snap acting mechanism to the position shown in Fig. 1.

Fig. 2.

The operation of the compressor will cause a reduction in temperature of the evaporator with the consequent eil'ect of reducing the temperature of the liquid in the bulb 41. When all of the liquid is condensed within the bulb 41, as shown in Fig. 3, the liquid is no longer subjected to the temperature oi the air and as soon as this liquid is subjected only to the evaporator temthe system is greatly reduced.

Since the system 45 starts the running phase of the compressor in response to the temperature of the air remote from the evaporator and starts the inactive phase in response to the temperature of the evaporator, a switch may be used having a wide diil'erential while still maintaining the desirable accurate temperature control. Switches with wide differential between the closing and opening thereof can be made ruggedly and at a lower cost than switches having a narrow diflerential.

When the present type, of control system is used, the compressor 2| is maintained operative until a desired minimum temperature is obtained in the evaporator. Also the compressor starts its refrigerating function when the air attains a predetermined high value. If desirable the capacity oi the bulb 41 and the liquid content oi the system 45 may be computed so that no liquid overflows from the 'bulb 41 to the bulb 44 until the temperature of the evaporator has attained a predetermined high 'value as, for example, above 32 degrees F. This will insure cyclical defrosting of the evaporator.

In the system I45 shown in Fig. 4 the bulb I41 is in the form of a bellows and is also in intimate thermal contact with the wall 24 01' the evapo-.

' liquid therein corresponding to the temperature of the air thereabout. ,When the air about 44 attains apredetermined desired low tempera- V causing an increase in pressure in the system This completes the circuit to the motor 2|. The liquid. 1 level at this time is diagrammatically shown in I45. This will cause expansion of the belows I41 until its capacity is sumcient to hold all of the liquid contained in the system I45. Obviously, all condensation will take place within bellows I41 when the bellows is expanded suilicient- 1y to retain all of the condensate because it is the coldest part of the entire system. As the temperature of the evaporator increases, the

pressure within system I45 will increase and when; the pressure within system I45 attains a predetermined high value, computed with respect to a maximum temperature'desired of the evaporator, the bellows 43 will have expanded sunlciently to close the switch 31 to start the compressor 2i. As previously stated, as the temperature oi the evaporator decreases, collapsing oi the bellows I41 will force liquid into the bulb 44. In this manner the running phase oi the compressor is sto ped when the temperature of the air attains a predetermined low value and the running phase of the cycle is started. when the evaporator attains a predetermined high temperature. By reason of this arrangement, cyclic defrosting of the evaporator can be assured, ifv

desirable, since the controller can be adjusted so that the compressor is not started until the evaporator attains a temperature above 32 degrees F.

The embodiment illustrated in Fig. 5 is similar to that disclosed in Fig. 4. In the embodiment shown in Fig. 5, there is provided a bellows I! in addition to the bellows I41. This bellows II is in intimate thermal contact with the evaporator wall 24 and contains a volatile fluid which is albellows I41 and in the particular illustration, it Y ways partly vapor and partly liquid within the normal range of operation oi the system. "This bellows is adapted to move toward collapsed and toward expanded positions, respectively, with decrease and increase in temperatures of the evaporator. It is arranged to augment the action of surrounds bellows I41. The effect of bellows I41 and 55 can be controlled by adjusting the tension oi the spring 58 by a thumb screw 51. By reason of this adjustment the temperatures at which the system I 45 responds may be varied.

The embodiment illustrated in Fig. 6 is also similar to that shown in Figs. 4 and 5, but in this embodiment bellows 58 opposes the bellows I41, that is when the bellows II and I41 are decreased in temperature the fluids contained in lower closed side of bellows 5! abuts a stationary plate 82 which is suitably attached to the yoke II. Pins 63 are attached to the plate I and to a plate 44. The spring 54 is interposed between the lower side of plate 42 and a spring cap II. A thumb screw 51 is threaded into the plate 44 and abuts the spring cap .5, and can be adjusted for changing the pressure of the spring It.

The bellows 59 is constructed or arranged to have an overpowering influence over the bellows I41. It may be larger in diameterso as to have a greater force than the bellows I41 with equal changes in temperature of the fluids contained therein, but in the embodiment illustrated it contains a fluid which is always partly liquid and partly vapor during normal operation but having the characteristics of being capable of greater changes in pressure than the bellows I41 with corresponding changes in temperature. Thus during cooling of both the bellows and I41, the collapsing effect of bellows 69 will be greater than the collapsing effect of bellows H1 whereby bellows I41 will be expanded, and. conversely during increase in temperature of bellows 59 and I41, the expansion effect of bellows 59 will be greater than bellows 1.

In the embodiment shown in Fig. 7, there is illustrated another well known compressor-condenser-expander type refrigerator. Instead of employing a float valve, as the pressure reducing element, there is shown a restrictor i1 interposed between the outlet of the pipe II and the inlet of the evaporator 28. Obviously this apparatus can be employed in connection with the other embodiment of the invention and vice versa. this system, bulbs I16 and 41 are employed but in addition thereto, a secondary system 68 is employed. This system I includes a bulb in the form of a coil of tubing 19 which intimately embraces bulb 48, a switch bellows ill and an interconnecting tube 1|. The bulb 41 is in intimate thermal contact with the evaporator and therefore assumes or closely follows the temperature thereof while the bulb 46 is remote from the evaporator and responsive to the temperature of the air in the inclosure 52.

During the heating phase of the evaporator 20, the liquid in-bulb l1 will overflow into bulb 46 and the liquid entering bulb 48 will assume the temperature of the air. As the temperature of the air increases, the pressure of the fluid within the coil 10, pipe 1| and bellows ill will increase and, when this pressure increases to predetermined high value, corresponding to a predetermined maximum desired temperature of the air, the switch 31 will be closed to start the running phase of the compressor II. This will cause cooling of the evaporator 20. The cooling of the evaporator will continue until the temperature of the bulb attains a predetermined low value, at which time the pressure within the bulb 10, pipe 1| and bellows I will be de-.

creased sufllclently to collapse the bellows H3 sufficiently to open the switch 31. The temperature of the bulb 10 must be decreased to a temperature considerably lower than the temperature of the air before the bellows is col- .lapsed sufficiently to open switch 31 and this cooling of the bulb 10 is eflected only after the evaporator 20 is cooled sufficiently to contract the liquid in the bulb 41 to such an extent that condensation of gas of the liquid is taking place in bulb 41. When condensation takes place in bulb 41, vaporization of the liquid in bulb I8 is taking place which in effect causes a material decrease in the temperature of the bulb 46.

Accurate temperatures can be maintained although the switch is opened at a relatively low pressure in bellows! and closed at a materially higher pressure. Here again a wide differential switch may be employed.

tion of the refrigerating apparatus when no liquid is contained within bulb 46, the secondary system II in itself will function tostop the refrlgerator compressor prior .to the cooling of the air to a detrimental state. This is accomplished by causing the secondary system it to be affected by the temperature of the outlet pipe 21. It is well known that when the evaporator is cooled excessively part of the refrigerant vaporizes in the pipe leading from the evaporator to the compressor. When this occurs there is a material reduction in the temperature of the outlet pipe. Therefore a bulb 12 of the thermostatic system is connected with the outlet pipe 21 by a tube 13. Now, in the event of excessive cooling, the bulb 12 will be decreased to a temperature sufflciently to reduce the pressure within the thermostatic system 68 sufficiently to collapse the bellows I" and open the switch 31. It is to be understood, however, that during normal operation, the bulb 10 is cooler than the bulb 12, and therefore, the bulb 10 normally controls the pressure in the secondary system it.

From the foregoing it provided a refrigerating apparatus in which the phases of the cycles. of operation thereof can be controlled from two diflerent zones as, for example. the evaporator and the air in which a rugged and inexpensive switch may be employed, since the control system operates between wide variations of temperature and pressure.

-While the forms of embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. Y

I claim:

l. Refrigerating apparatus comprising in combination, a heat absorber: means for cyclically circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a. volatile liquid, one portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber, the quantity of liquid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operating temperature of the heat absorber the capacity of said portion is insufficient to hold all said liquid, a second portion of said system being subjected to the medium cooled by the heat absorber and being'connected with the first ment oned portion to receive the excess liquid from the' first mentioned portion when the heat absorber is at the second mentioned operating temperature, and means responsive to condensation of the gas of the liquid in the first mentioned portion of said system for changing from one of the phases of the cycle of the circulating .means to the other.

2. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber, the quantity of liquid conwill be seen that I have -mcans to the other.

tained in said system and the relative capacity said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorberand under another normal operating temperature of the heat absorber the capacity of said portion is insufilcient to hold all said liquid, a second portion of said system being subjected to the medium cooled by the heat absorber and being connected with the first mentioned portion to receive the excess liquid from the first mentioned portion when the heat absorber is at the second mentioned operating temperature, and means responsive to a change in pressure in said system when condensation of the gas of the liquid takes place in the first mentioned portion for changing from one of the phases of the cycle of the circulating 3. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber, the quantity of liquid contained in said system and the relative capacityof said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operatingtemperature of the heat absorber the capacity of said portion is insufiicient to hold all said liquid, a second portion of said system beingsubjected to the medium cooled by the heat absorber and being connected with the first mentioned portion'to receive the excess liquid from the first mentioned portion when the absorber is at the second mentioned operating temperature. and means responsive to a change in temperature of the second mentioned portion of the system when condensation of the gas of-the liquid takes place in the first mentioned portion for changing from one of the phases of the cycle of the circulating means to the other.

4. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one

portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber, the quantity of liquid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operating temperature of theheat absorber the capacity of-sald portion is insufiicient to hold all said liquid, a second portion of said system being subjected to the medium cooled by the heat absorber and being connected with the first mentioned portion to receive the excess liquid from the first mentioned portion when the heat absorber-is at the second mentioned operating temperature, and means responsive to the pressure in said system when all the liquid is present in the first mentioned portion for changing from one of the phases of the cycle of the circulating means to the other and responsive to a predetermined pressure in the system when part of the liquid is contained in the other portion of the system for changing from.

said other'phase of the cycle to the said one phase.

5. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclicall: circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber, the quantity of liquid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operating temperature of the heat absorber the capacity of said portion is insufilcient to hold all said liquid, a second portion of said system being subjected to the'medium cooled by the heat absorber and being connected with the first mentioned portion to receive the excess liquid from the first mentioned portion when the heat'absorber is at the second mentioned operating temperature, and means responsive to the pressure in said system when all the liquid is present in the first mentioned portion,

for changing from the running phase of the cycle of the circulating means to the inactive phase and responsive to a predetermined pressure in the system when part of the liquid is contained in the other portion of the system for changing from said inactive phase to the running phase.

6. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of, said system being responsive substantially solely and at all times to the temperature -ofthe heat absorber, the quantity. of liquid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operating temperature of the heat absorber the capacity of said portion is insufficient to hold all said liquid, a second portion of said system being subjected to the medium cooled by the heat absorberand being connected with the first mentioned portion to receive the excess liquid from the first mentioned portion when the heat absorber is at the second mentioned operating temperature, and means responsive to the pressure insaid system when all the liquid is present in the first mentioned portion for changing from the inactive phase of the cycle of the circulating means to the running phase and responsive to a predetermined pressure in the system when part of the liquid is contained in the other portion of the system for changing from said running phase to the inactive phase.

7,. Refrigerating apparatus comprising in combination, aheat absorber; means for cyclically circulating refrigerant through the absorber,

each of the cycles including a running phase and an inactive phase; and control means including a closed system; containing a volatile liquid, one portion of said system being respo sive substantially solely and at all times to the temperature of the heat absorber, the quantity of liqid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion when the heat absorber is relatively cold and lnsufllcient to hold all of said liquid when the heat absorber is relatively warm during normal operation of the refrigerating apparatus, and means responsive to condensation of the gas of the liquid in the first mentioned portion of said system for changin from one of the phases of the cycle of the circulating means to the other.

8. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being responsive substantialLv solely and at all times to the temperature of the heat absorber, the quantity of liquid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion when the heat absorber is relatively cold and insufficient to hold all of said liquid when the heat absorber isrelatively warm duringnormal operation of the refrigerating apparatus, and means responsive to a change in pressure in said system when condensation of the gas of the liquid takes place in the first mentioned portion/for changing from one of the phases of the cycle of the circulating means to the other.

9. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each or the cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being'responsive substantially solely and at all times to the temperature of the heat absorber, the quantity of liquid contained in said system and the relative capacity of said portion being such that all of said liquid is contained in said portion when the heat absorber is relatively cold and insuflicient to hold all of said liquid when the heat absorber is relatively warm during normal operation of the refrigerating apparatus, and means responsive to a change in temperature of the second mentioned portion of the system when condensation of the gas of the liquid takes place in the first mentioned portion for changing from one of the phases of the cycle of the circulating means to the other.

10. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of said cycles including a running phase'and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system having a capacity variable with changes in temperature and the quantity of liquid contained in said system and the capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature to which said portion is subjected and under another normal operating temperature the capacity of said portion is insufficient to hold all said liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said portions being spaced from one another and subjected to different temperatures, and means responsive to condensation of the gas of the liquid in the first mentioned portion of said sys tem for changing from one of the phases of the cycle of the circulating means to the other.

11. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system having a capacity variable with changes in temperature and the quantity of liquid contained in said system and the capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature to which said portion is subjected and under another normal operating temperature the capacity of said portion is insufflcient to hold all said liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said portions being spaced from one another and subjected to different temperatures, and means responsive' to a change in pressure in said system when condensation of the gas of the liquid takes place in the first mentioned portion for changing from one of the phases of the cycle of the circulating means to the other.

12. Refrigerating apparatus comprising in, combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber and having a capacity variable with changes in temperature of the heat absorber and the quantity of liquid contained in said system and the capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operating temperature of the heat absorber the capacity of said portion is insufficient to hold all said liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said second mentioned portion being subjected to the medium cooled by the heat absorber, and means responsive to condensation of the gas of the liquid in the .first mentioned portion of said system for changing from one of the phases of the cycle of the circulating means to the other.

13. Refrigerating apparatus comprising in combination, a. heat absorber; means for cyclically circulating refrigerant through the absorber, each of said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being :responsive substantially solely and at all times to the temperature of the heat absorber and having a capacity variable with changes in temperature of the heat absorber and the quantity of liquid contained in said system and the capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of the heat absorber and under another normal operating temperature of the heat absorber the capacity of said portion is insufiicient to hold all said liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said second mentioned portion subjected to the medium cooled by the heat absorber, and means responsive to achange inpressure in saidsystemwhen condensation of the gas of the liquid takes place in the first mentioned portion ior changing from one of the phases of the cycle of the circulating means to the other.

14. Refrigerating apparatus comprising in combination, a heat absorber; means forcyclically *circulatinl refrigerant through the absorber, each or said cycles including a runningphaseandaninacflvephase; and controlmeansy including a closed system containing a volatile liquid, one portion of said system having a capacity variable with changes in temperature and the quantity of liquid contained in said system and -thecapacityoisaidportionbeingsuchthatall second mentioned operating temperature, said portion being spaced from one another and sub- .iected to difierent temperatures, and means re- .sponsivetothepressureinsaidsystemwhenall the liquid is present in the first mentionedportion for changing from one of the phases oi the cycle of the circulating means to the other and responsive to a predetermined pressure in. the system when part of the liquid is contained in the other portion oi the system for changing containedinsaidsystemandthecapacityoisaid I pacity variable with changes in temperature of the heat absorber and the quantity or liquid portionbeingsuchthatalloisaidliquidiscontained'insaidportionunderonenormaloperating temperature of thehcat absorber and under another normal operating temperature of the heat absorber the capacity of said portion is in- 'sumcienttoholdallsaidiiquidasecondportion 10.

ot'said system being connected with the first mentioned portion to receive theescess liquid whenthefirstmentionedportionisatthesecond mentioned operating temperature, said second 4 mentioned portion being subjected to the medium 15 cooled by the heat absorber, and means responsive to the pressure in said system when all liquid is present in the first mentioned. portion tor changing irom the inactive phase of the cycle oi. the circulating means to and goresponsivetoapredeterminedpressureinthe from said other phaseoi' the cycle to the said one phase.

15. Refrigerating apparatus comprising in combination, a heat absorber:-means {or cyclically circulating refrigerant through the bf sorber, each or said cycles including a running phase'and an inactive phase: and control means including a closed system containing a volatile liquid, one portion of said system having a capacity variable with changes in temperature and the quantity oi liquid contained in said system and the capacity oi said portion being such that all of said liquid is contained in said portion under one normal operating temperature to which said portion is subiected and under another normal operating temperature the capacity oi said portion is insufiicient to hold all said liquid, a second portion oi said system being connected withthe first mentioned portion to receive the excess liqold when the first mentioned portion is at the second mentioned operating temperature, said portions being spaced from one another and subjected to difi'erent temperatures, and means responsive to the pressure in said system when all liquid is-present in the first mentioned portion for changing from the inactive phase oi the cycle or the circulating means to the running phase and responsive to a predetermined pressure in the system when part of the liquid is contained in the other portion 01 the system for changing from said running phase to the inactive phase.

16. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each oi said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system being responsive substantially solely and at all times to the temperature of the heat absorber and having a ca-.

system whenpart oitbe liquidiscontained in the other portion oi the system i'or changing from said running phase to the inactive phase.

17. Refrigerating apparatus comprising in combination, a heat absorber; means tor cyclically circulating refrigerant through the absorber, each oi said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion oi said system having a capacity variable with changes in temperature, means responsive to temperature for varying the capacity at said ortion, the quantity oi! liquid contained in said system and the capacity of said portion being such that all oisaid liquid is contained in said system and the capacity'ot said portion being suchthatalloisaidliquidiscontainedinsaid portion under one normal operating temperature of said temperature responsive means and under another normal operating temperature oi the excess liquid when the first mentioned portion is at the second mentioned operating temperature. said temperature responsive means and the second mentioned portion of said system being spaced from one another and subjected to dit- Ierent temperatures, and means responsive to condensation of the gas of the liquid in the first mentioned portion of said system for changing from one of the phases of the cycle of the circulating means to the other.

l8. Refrigerating apparatus comprising in combination, a, heat absorber; means for cyclicall circulating refrigerant through the absorber, each oi said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system having a capacity variable with changes in temperature; means responsive to temperature for varying the capacity of said portion, the quantity of liquid contained in said system and the capacity of said portion being such that all oi said liquid is contained in said portion under one normal operating temperature oi said temperature responsive means and under another normal operating temperature of the temperature responsive means the capacity oi said portion is insufiicient to hold all said liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, saidtemperature responsive means and the second mentioned portion of said system being spaced from'one another and subjected to different temperatures; and means responsive to changes in pressure in said system when condensation of the gas of the liquid takes place in the first mentioned portion for changing from one of the phases of the'cycle of the circulating means to the other.

19. Refrigerating apparatus comprising in combination, a heat absorber; means'for cyclicaily circulating refrigerant through the absorber, each of said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid; one portion'of said system having ;a capacity variable with changes in temperature, means responsive solely and at all times to the temperature of the heat absorber for varying the capacity of said'portion, the quantity of liquid contained in said system and the capacity of said portion being such that "all of said liquid is contained in said portion under one normal operating temperature of said temperature responsive means and under another normal operating temperature of the temperature responsive means the capacity of said portionis insuificient to hold allsaid liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said second mentioned ortion being subjected to the medium cooled by the heat absorber, and means responsive to condensation of the gas of the liquid in the first mentioned portion of said system for changing from one of the phases of the cycle of the circulating means to the other.

20. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the absorber, each of said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid, one portion of said system having a capacity variable with changes in temperature, means responsive solely and at all times to the temperature of the heat absorber for varying the capacity of said portion, the quantity of liquid contained in said system and the capacity of said portion being such that all of said liquid is contained in said portion under one normal operating temperature of said temperature responsive means and under another normal operating temperature of the temperature responsive means the capacity of said portion is insufficient to hold all said liquid, a second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said second mentioned portion being subjected to the medium cooled by the heat absorber, and means responsive to a. change in pressure in said system when condensation of the gas of the liquid takes place in the first mentioned portion for changing from one of the phases of the cycle of the circulating means to the other.

21. Refrigerating apparatus comprising in combination, a 'heat absorber; means for cyclically circulating refrigerant through the ab sorber, each of said cycles including a running phase and an inactive phase; and control means means responsive'tp temperature for varying the capacity of said portion, the quantity of liquid contained in said system and the capacityof said portion being such that all of saidliquid is contained'in said portion under one normal oper-' ating temperature of saidi temperature responsive means and under anothernormal operating tem perature of the temperature responsive means the capacity of said portion is insuflicient to hold tioned portion is at the second mentioned oper-' ating temperature, saidtemperature responsive means and the second mentioned portion of said system being spaced from one another and subjected to different temperatures, and means responsive to the pressurein said system when all the liquid is present in the first mentioned portion for changing from one of the phases of the cycle of the circulating means to the other and responsive to a predetermined pressure in the system when part of the liquid is contained in the other portion of the system for changing from said other phase of the cycle to the said one phase.

2 2. Refrigerating apparatus comprising in combination, a-heat absorber; means for cyclically circulating refrigerant through the absorber, each of said cycles including a running phase and an inactive phase; and control means including a closed system containing a volatile liquid; one portion of said system having acapacity variable with changes in temperature, means responsive totemperature for varying the capacity of said portion, the quantity of liquid conperature of the temperature responsive meansv the capacity of said portion is insuflicient to hold allsaid liquid, 9. second portion of said system being connected with the first mentioned portion to receive the excess liquid when the first mentioned portion is at the second mentioned operating temperature, said temperature responsive means and the second mentioned portion of said system being spaced from one another and subjected to different temperatures; and means responsive to the pressure in said system when all liquid is present in the first mentioned portion for changing from the inactive phase of the cycle of the circulating means to the running phase and responsive to a predetermined pressure in the system when part of the liquid is contained in the other portion of the system for changing from said running phase to the inactive phase.

23. Refrigerating apparatus comprising in combination, a heat absorber; means for cyclically circulating refrigerant through the abincluding a'closed system containing a volatile liquid: one portion of said system having acapacity variable with changes in temperature,

mids tamedmmaminmdtneumwosma portionheinz'euehtheteilofaidiiqnidiscohtainedin said portion under'one normal opersting temperatureotaeidtempereture remomive means and under .nnother normal operating tempereture oi the temperehire. responsive meme thecapacityoinidportioniginmmeienttohold 'anuunquieamnam um Minimal-11th h iirltpor tion to receivethe excess liquid when mentioned portion is at the seeond'mentioned operating temperature, said second mentioned present in the first mentioned portion tor chanp in: from the inactive phase 0! the cycle or the 'cireuiatinz'menns'to the runningphue nndre-' s pomiveto a predetermined pree'eure in the syntax: when MOf the liquid is eontnined in theotherportionoi'thesy'stemiorcheuing i0 tromeeidnmningphuetotheimetivephue.

WALTER v. nouns. 

